Providers of telecommunication services typically offer plans that incentivize subscribers to call at non-peak hours, such as nights and weekends. These plans also often include discounted or free calls between subscribers of a same service provider. Calls between subscribers to a same service are typically referred to as “mobile-to-mobile” calls, regardless of whether the devices participating in the calls are “mobile” telecommunication devices, such as cellular phones.
To offer discounted or free mobile-to-mobile calls, a telecommunication service provider determines whether a newly-received call from one of its subscribers is directed to another one of its subscribers. One technique used to determine whether a call is mobile-to-mobile involves the retrieval of information associated with the serving subscriber from subscriber databases. Those databases include home location registers (HLRs) and visitor location registers (VLRs) accessed via a Signaling System Number 7 (SS7) network of the telecommunication service provider. A Service Control Function (SCF) node of the telecommunication service provider that is tasked with determining whether a call is mobile-to-mobile queries the subscriber databases and makes the determination based on the information retrieved from those subscriber databases. This technique often results in substantial congestion of the SS7 network and reduced performance of the subscriber databases given the utilization of that network and those databases for other functions of the telecommunication service provider.